Good Day OpenFoamer's! Fist of all I want To sorry for my English,
but I certain, that your understand me....
I want to assign question...
Possible in OpenFoam to assign internal boundary condition - for example,
border between gas and fluid and sew(unit) solution on this border...

For example, I have three parallel line: between first and second line I have a gas,
between second and third line I have a fluid - second line is internal borber...
Both areas has general input and output borders......
How I can join two solution?